Several designs of machines are known and widespread for extemporarily preparing hot beverages in the form of infusions, e.g. coffee, tea, herb teas and the like, from a single-use and generally single-dose capsule or pod. Such machines are typically located at workplaces and public premises in general, and also versions for household use have spread.
In such machines, the end beverage is obtained through a process of so-called “extraction”. Said process consists in having a single-dose pod or capsule containing a product in granular or particle form be passed through by a high-temperature liquid, typically water. The liquid, downstream of such “infusion” through the pod or capsule, makes the desired beverage and is then dispensed to the consumer.
Such extraction and dispensing process is carried out in a dedicated unit of the machine that must be capable of:                receiving the capsule,        carrying out the actual infusion,        ejecting or allowing ejection of the used capsule, and        getting ready to receive a new capsule.        
This operation sequence is typically performed automatically, through mechanisms controlled in a coordinated way to:                selectively bring an infusion head near to a capsule holder,        cause dispensing of the liquid through the capsule by the infusion head,        remove the infusion head from the capsule holder, and        move the capsule holder so as to cause ejection of the used capsule and its repositioning in an arrangement for receiving a new capsule.        
The configuration in which the capsule holder is in a position for receiving a new capsule, and that in which this causes the ejection of a used capsule, are generally referred to as “armed configuration” and “disarmed configuration”, respectively.